Advice Needed – Building a Large Breeze Block Garden Studio (40m²+)

[optimystery]

Hi everyone,

I’m planning to build a large garden art studio (bigger than 30m²) and need advice on breeze block construction. Most search results focus on small prefab garden rooms, but I’m after something more like a garage or workshop—solid, durable, and cost-effective.

I know it will need to be no larger than 50% of the garden space.

Key Features:
• Size: Likely 40m²+
• Height: One long side needs to be tall for the painting wall
• Construction: Breeze block walls with flat or pitched roof, and double glazing, electric and plumbing for a washup area. Floor ideally waterproof. Walls covered in plywood ideal for stapling canvas and paper easily.
• Insulation: Probably cavity wall + insulation, but open to advice
• Budget: Looking for a cost-effective build, not a high-end architect project.

Questions:
1. Anyone built something similar? Any case studies or photos?
2. Cost Estimates – What did you pay for materials & labour?
3. Best Way to Find Builders? Would general builders or garage builders be best?
4. Planning Permission & Regulations – Any issues with getting approval for a large outbuilding?
5. Roof Recommendations – EPDM flat roof vs. pitched felt/tiled roof?
6. Best insulation approach for a blockwork studio?

I’d love to hear from anyone who has built a workshop, artist studio, or large outbuilding with similar construction. Any tips, photos, or builder recommendations would be massively appreciated!

Thanks in advance!

[Russell griffiths]

More details needed. 
is this just a hobby, one weekend a month, just in the summer, or full time work space 8-5 all year round, heating in the winter, cooling in the summer. 
lots of glass for natural light, or is that a no no for painting. 
what’s the access like to get to the build site, this could dictate a build method. 
what do you want it to look like

blocks can’t be left bare so it will need either rendering or cladding in something. 
fire regs, how close to a boundary is it, this will dictate the outer finish options. 
 

and the budget, what do you actually want to spend. 

[optimystery]

Thanks Russell,

 

This is more of a daily activity, so it will need to be comfortable all year round.

Probably some skylights would be good for light yes, and I would also have blinds if I need to use a projector.

If skylights add a lot to cost then maybe on the walls. The highest wall at the back will need to be window-free.

This is a plan that involves buying a new house with a big enough garden, so I don't know the access yet. That said, most houses where I'm looking will have fairly limited access.

I'd like it to look nice, and might consult an architect or have a go at designing myself with advice. But not architect magazine nice if you get what I mean.

Cladding would look a lot nicer, but I will be trying to keep costs as low as possible.

I don't really even know what the ballpark budget would be for something like this. Does under £50k sound feasible, including the plumbing?

Edited January 29 by optimystery